"That's how we met," she said on Ryan Seacrest's KIIS-FM radio show. "I was really excited to work with Chad because he's also a musician. We wrote a bunch of songs together, became really good friends, and now we have a wedding coming up."

Lavigne refused to confirm a date for the ceremony but said that she is "very excited", adding: "It's [going to be] kind of just a lot of close friends and family - it is sort of smaller.

"It's going to be quite spectacular, and there's a theme to it and we're going pretty big. But Chad doesn't even know everything yet!"

Lavigne also explained that she is planning to wrap sheet music from one of their collaborations around their wedding cake, while Kroeger hinted that they might perform a duet together at the ceremony.

The couple opened up about their engagement, too, with Lavigne explaining that Kroeger popped the question just one month after dating.

"We started dating - the next day, he's like, 'You know I'm going to marry you', and I said, 'I know'," she revealed. "It was just one of those things - we knew. We met in the studio and he proposed in the studio."

Meanwhile, Kroeger admitted that he was nervous about going down on one knee, explaining that he got the ring just 20 minutes before proposing in case he lost his nerve.

"I was like, 'I'm jumping out of the plane'," he said. "I was nervous. You know, it's funny - you can go and travel the world and you can sing songs to thousands of people and not even have your heartbeat race at all. You get down on one knee and commit yourself to a woman for the rest of your life... I was very nervous."

Lavigne offered further details of the proposal, saying: "The only thing that was weird was we usually go to the studio together and he had gone before me. I've been making this scrapbook of my time in the studio with a Polaroid camera - the only thing that was weird is that I walked into the studio and he was putting a picture in the book.

"And all of a sudden I walk over and he had taken a photo of himself holding the ring box and put the Polaroid in my scrapbook. And because I had stickers everywhere, he put in, 'Will you marry me?' It was really romantic."